Sayyiduna Abdullah bin Umar (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever keeps a dog other than a hunting dog or a dog for guarding livestock, two qirats will be deducted from his reward every day."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 11025